Platen-clutch for typewriting-machines



C'. GABRIELSON.

PLATEN CLUTCH FOR TYPEWRIT-ING MACHINES. APPLICATION man rfa. 5, 1919.

. C. GABRIELSON.

PLATEN CLUTCH FOR TYPEWRITING MACHINES.

APPLICATIONFILED FEB. 5, I9l9.

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MATEN-'CLUTCH non TYrEWm'rING-MACHINES.

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lqiplicationy filed February 5.1919. l Serial No. 275,175.

` ratchet wheel to a typewriter platen, but

y tion is embodied;

l which permits the platen tobe released soi that it maybe turned while the ratchet wheel 'is stationary Yfor firregular spacing and. other purposes. The invention is illustrated in the accompanying drawings in which y q Figure 1 is a central longitudinal ,sec-

i tional view Vof a platen in which the inven- Fig. 2 is Aan enlargedsection of one end "of the platen, in la plane at right angles to the plane of section of Fig. l.` Fig. `2 illustrates the position of the parts with the ratchetjwheel locked to the platen; y l

Flig. 3`i`is` a view similar to Fig.f2 but i showing the position of the parts whenthe platen is free from the ratchet wheel;

` Fig. 4 is anend view ofthe platen with `one of theheads removed'to show the clutch gmechanism, the shaft being shown in sec tion;A

l l 5i is adetail ofmeans for holding the clutching mechanism in the released pos1- tien- V` v 4Fmgj a section on the line 6-6 of Fig. 5; and y Fig. 7 is a perspective view of the rocking member of the clutch mechanism.

` Referring to the drawings 10 indicatesthe wooden core of atypewriter platen,` 11 the hard rubber sleeve surrounding the core, 12 the left head of, theplaten which is suitably attachedfto the' woodencore and 13 the left knob for turning the platen which is `mounted cna short shaftv iixed in the head A 12. These parts are of ordinaryl construction, excepting that the wooden core is bored out ina peculiar manner as will be presently describe' l The platen 10 hasa largeV bore or axial 1 opening 14 at its right hand and ,a 'smaller bore 15 at its left end, thusproviding an intermediate shoulder 16. At the right end A of the platen there is attached a circular @las i? havn-g e mais es ce here Specification of Letters Iiatent.

rammed oet. ii, rear.

ratchet coperates fwith the usual spring holding pawl or roller 25 and with a line space `feed pawl,not shown. On the outer side of the bearing'21 and the ring 23 there is a concentric cap 26. The ring 17 the bear- Aing 21,'andthe cap `26 arerigidl-y connected together by means of suitable screws 27.. "The, rollers 22 fit the annular space .between the bearing 21 and the ring 23. When these rollers are freer the platen may be turned independently of the ratchet wheel by turnthepl'aten shaft 28, which is rigidly fixed in the head 26, or by turningrthe knob 13.

A 'rockingdevice for operating the clutch,

is shown in Fig. 7. Thehead 29 of this dei vice is annular and the shaft 28 passes loosely `through it. Radially extending from one `side of the head 29 is a boss 30 which is thering bearing 21, as shown in Figs. 1 and 4. `Diametric`all`y opposite, the boss 30 is an arm 324 which is flattened on two sides,- thus providing a substantially rectangular `pivotally mounted on a screw 3l,`mounted in is turned on its aXis about the screw 31 the Y squared end 33 presses the rollers apart and takes up all slack in the raceway, thus clamping theJ ratchetV wheel to the race ring, which is rigidly connected to the platen. Under these circumstances, the platen must turn with' the ratchet wheel. To normally hold the parts in this position, l provide the arms 34 on .the rocker' (Figs. 1, 2 and 7). `The free ends of these arms engage cam surfaces 35 on oppositesides of a cam .block 36 mountedon vtheshaft 28 withinV the platen. The Acam block is normally pressed to the right by a spring surrounding the shaft 28 and abutting against the nut or shoulder 38. At'the other "end-the spring bears on the Y cam` block forcing it to the right and holding the arms in the position shown in FigQ 2 in l wheel the cam block 36 is moved to the left against the pressureof the spring 37, permitting the arm 34 to drop or move into the inner sleeve 42.

position shown in Fig. 3. This is accomplished by means of a rod 39, one end of which `engages a projection 40 on the cam block 36, while the other end extends out into position to be engaged by a smaller knob 41 on the'right end of the platen shaft. The rod 39 lies in a groove in one side of the platen shaft 28 and is slidable therein. The right end of the 'rod 39 normally projects Vbeyond the right end of the platen shaft 28. 'On Lthe right end .of the platen shaft there is mounted a sleeve 42 which, as shown, is integral with the knob 41. Upon this sleeve is mounted a second sleeve 43, upon which is fixed a twirling knob`44. The'knob has a limited movement on the shaft, longitudinally, but turns the shaft by means of pin i 45 which is fixed on the shaft and extends through slots in the sleeves 42 and 43, as shown in Figs. 2 and 6. The kpin and the slot in the sleeve 43 are covered by means of a cylindrical projection 46 which is integral with the knob 41, as shown in Fig. 2. The

sleeve, 43V is retained lengthwise on the sleeve 42 bymeansY of the nut 47 on one-end and the pin 45 rat the other. f f i When it is desiredto release the platen il y,fromvthe line space-ratchet the knob 41 is pressed to the left into the position shown in Fig. V3.v This presses the rodA 39 to the left-and moves the cam block 36 compressing 22 are released and freed, as previously stated, permitting `the platen to be turned to any extent withoutfturning the ratchet wheel. On releasing the knob 41 the spring 37 moves the cam block,rod 39, and knobs 41 and'44 to the right into normal position.

If it be desired to hold the parts-in the position shown in Fig. 3 with the platen free from the ratchet ring, this may be accomplishedA by turning the knob-41 so asto engage the pin 45 in the recess 48 cut in the This will prevent the vspring 37 from acting-untilthe knob 41 is turned in the reverse direction.

What 1 claim and desire to securer by Letters Patent is: Y

1. The combination with: a typewriter platen and av ratchet ring thereon of rollers carried bythe platenl andon which said ring is vmounted and means lfor crowding the -rollersin their raceway to clamp the ring to the platemsaid means comprising a part extending into the race between the rollers and means for turning said part to exert separating pressure on and crowd the rollers.

2. The combination with a typewriter platen of an annular race fixed on the platen, rollers in said race a. ratchet ring surrounding and running on said rollers and spring operated means for normally crowding the rollers in the race to lock the ratchet ring to the platen, said means comprising a part adapted to turn on an axis at right angles to the axis of the platen and having a noncircular portion extending between the rollers.

1n a typewriting machine the combination with a platen of a head fixed to said platen and a shaft fixed in the head and centrally arranged in the platen, an annular race in the head, rollers in said race, a ratchet ring mounted on said rollers, means l adapted to crowd the rollers to lock the ring vthe locking of the ratchet ring to the platen.

v 4. 1n a typewriting machine the combination with a platen of a head fixed to the platen, a shaft axially arranged in the platen and fixed to the head, a knob on said Shaft for turning the platen, a ratchet ring mounted on the platen head, a cam device movably mounted on said shaft, a spring for moving said cam in one direction and means for moving the cam in the opposite direction against the pressure of the spring, and a device operated bythe cam under the pressure of the spring for locking the ratchet ring to the platen.

5. 1n a typewriting machine the combination with a platen of a roller race fixed to the platen at one end thereof, rollers in said race, a ratchet ring mounted on said rollersyarocking device having its axis at right angles to the axis of the platen and having a non-circular projection extending into the race between the rollers, a spring normally tending to move the rocking device into position to crowd the rollers and clamp lmounted thereon of a ratchet ring mounted on the platen with freedom for relative movenient` a spring operated device mounted on Y the shaft for normally clutching the ratchet ring to the platen, a knob slidably mounted on the end of the shaft, means for connecting the knob with the clutching device .whereby a longitudinal movement of the knobA will unclutch the ratchet ring and means for locking the parts in position to hold the ratchet ring free whereby the platen may be turned independently thereof.

7. The combination with a typewljtl .130

rollers in said race, a ratchet ring mounted on Vsaid rollers and means for crowding the rollers to look the ratchet ring to the platen, said means including an abutment extending into the roller race at one point thereof and a device extending into the roller race at another point thereof and means for turning said device to crowd the rollers against the abutment and lock the ratchet ring to the platen.

8. ln a typewriting machine the combination with a platen of a head fixed to said platen and a shaft fixed in thehead and centrally arranged inthe platen witha surrounding chamber, an annular race in the head, rollers in said race, a ratchet ring mounted on said rollers, meansadapted to crowd the rollers to lock the ring to the platen, a cam mounted on said shaft within the platen adapted to control said locking means, a spring for normally holding said cam in locking position, and means extending from said cam through said head and shaft for manually moving said cam to unlocked position.

9. in a typewriting machine the combination with a platen of a head iXed to said platen and a Shaft fixed in the head and centrally arranged in the platen with a surrounding chamber, an annular race in the head, rollers in said race, a ratchet ring mounted on said rollers, means adapted to crowd the rollers to lock the ring to the platen including a pivoted member having a pawl extending within the platen and a cam mounted on said shaft within the platen and spring operated to turn said pivoted member through said pawl to normally ef fect the locking of the ratchet ring to the platen.

In testimony whereof l aiix my signatureo y CARL GABRELSUN. 

